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Our bodies are made up by cells containing our own DNA. Plus
10 times as many with foreign DNA. The bacteria found on our skin, and inside
our organs (intestine, vagina, mouth, nose, etc.) are referred to as our “microbiome”, outnumber our own cells by 10 to 1,
and make up a vital organ with independent functions essential to our
existence. Among other things bacteria in our gut help us metabolise nutrients
and vitamins that we cannot otherwise process, and they assist our immune
system in keeping pathogenic organisms at bay. We also refer to these bacteria
as “commensals”.

Now, many of us also harbour intestinal parasites. Globally,
billions of people are infested by worms (e.g. pinworm) and/or amoebae
(more correctly, “protists”), at least at some point in their lives. Many of
these parasites are non-pathogenic to otherwise healthy individuals. They are transmitted faecal-orally, either directly (personal contact) or indirectly (cysts
surviving in the environment (water, food, soil, etc.), and keeping infectious
for a given period of time).

One of the most common parasites – if not the most common –
found in humans is Blastocystis. It
is possible that more than 1 billion people harbour this parasite, and there is
indicative evidence that it may cause intestinal symptoms, although it is also
clear that many people are colonised by Blastocystis
without experiencing symptoms. We therefore investigate the role of this
parasite in health and disease.

So, why this blog? Well, due four major reasons:

1) Obligation. I
have been working with Blastocystis
since 2005. I’ve raised more than €600,000 for Blastocystis research, and the output from my research is published
in journals that are not publicly accessible unless you pay. I feel a certain
obligation towards the general public in terms of sharing my results and experience.

2) Information.
There is a lot of information on the internet about Blastocystis, much of which is unsupported and potentially misleading.
With this blog I try to convey un-biased information and facts that have been
documented in scientific journals. Not that this is necessarily always the absolute
truth. But I believe that by keeping to facts we will much faster get to grips
with the clinical significance of Blastocystis
and learn how to deal with it, if we need to deal with it.

3) Resource. I
(will) dedicate some of the posts or pages on this blog to Blastocystis-related resources, such as laboratory protocols, SOPs,
etc. For instance, I hope that this blog will be useful and inspiring for
students and even for colleagues who have already experience in Blastocystis research.
Getting a clear
picture of the subtype distribution of Blastocystis
in humans and non-human hosts across the globe is central to my ambition, and I
want to advocate for the use of “barcoding” and the web site www.pubmlst.org/blastocystis for
fast and standardised identification of Blastocystis
subtypes based on sequence data; it allows for bulk submissions as well. If you
want to have your sequences along with provenance data deposited in the
database, please contact me and I will be happy to assist you.

4) Comment.
Sometimes I’m posting comments on Blastocystis-specific
papers or interesting papers from related research fields. I’m especially
interested in the human intestinal microbiome, and how we can study the
interaction between the host and common endo-symbionts (bacteria as well as Blastocystis and other protists).

If you want to leave a comment, you can either log in to
Blogger and comment on a particular post, or you can find my email on my blogging
profile and email me.

I use Google AdSense hoping that I can get enough revenue to cover expenses related to web hosting.

Thoughts on Blastocystis in Amazon

On Blastocystis

Blastocystis is a protist parasitising the intestine of humans and a variety of animals. We estimate that at least 1 billion people worldwide are colonised by this parasite, most of whom probably experience no more episodes of intestinal upset, e.g. diarrhoea, than the average individual. In any case, many people have Blastocystis wihtout knowing and without feeling sick. Blastocystis may colonise the intestine for a long time (i.e. months or years).Many species of Blastocystis have been acknowledged, of which at least 9 have been found in humans. Such species are currently termed "subtypes" (STs). ST1, ST2, ST3 and ST4 are common in Europe. While ST1, ST2, and ST3 appear to have equal prevalences in patients with diarrhoea and healthy individuals, ST4 appears to be epidemiologically linked to diarrhoea and/or chronic conditions such as irritable bowel syndrome (IBS).

There is no known efficient eradication strategy for Blastocystis. Although metronidazole is often prescribed for Blastocystis infections, there is conflicting reports on its efficacy. Even in combination with a luminal agent, such as paromomycin, Blastocystis eradication cannot be guaranteed. Read more here.

I'm very interested in studies aiming to explore1) Blastocystis in the environment2) Why some people are colonised while others are not3) Whether Blastocystis colonisation requires a certain intestinal flora (e.g. enterotype) to establish4) To which extent human Blastocystis is acquired from animal reservoirs5) Potential differences in virulence between subtypes or strains (by for instance comparative genomic studies)

During my Blastocystis research, I and my colleagues have discovered/developed1) New Blastocystis species2) Precise molecular methods for accurate detection (PCR)3) High resolution typing systems (MLST) for strain identification of Blastocystis4) A standardised nomenclature for Blastocystis5) A publicly available database for identification of subtypes and sequence data despository (please see links below)

Using microscopy-, culture-based and molecular tools we have generated data that have shed light over the transmission and distribution of Blastocystis subtypes in human and animals.